Rotary pump



A. BAUMANN 1,765,360

ROTARY PUMP June 24, 1930.

Filed Feb. '7, 1927 3 Sl'xeets-heefr. 1

AQ BAUMANN June 24, 1930.

ROTARY PUMP Filed Feb. '7, 1927 3 Sheets-Sheet 2 A. BAUMANN June 24,1930.

ROTARY PUMP Filed Feb. 7, 1927 3 Sheets-Sheet 3 l; ffii/Iliff.

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. lill. lil Il!! Patented June Z4, 1930 UNITED STA-TES ..ADOLPHBA'UMANN, OF BADEN, SWITZERLAND, ASSIGNOR T0 AKTIENGESELLSCHAFT i'BROWN'. BOVERI'GU CIE., OF BADEN, SWITZERLAND, JOINT-STOGK COMPANY 0FSWITZERLAND ROTARY Puur Application led February 7, 1927, Serialv No.

This invention relates to rotary pumps,l and it has particular relationto pumps in which the liquid is impelled in an -elastic tube by means ofa suitable impeller member that progressively compresses the tube andsqueezes the Huid along the same.

The pumps of the foregoing type as known heretofore, have provendelicient on account of the excessive wear of the hollow tube in whichthe liquid is being impelled the limitations in respect to the pressureunder which such pumps could operate; the necessity of packing means andstuiiing. boxes; and other drawbacks incident to the'manufacture andoperation of the same.

Among the objects of the' present invention is to provide a pump of thistype which overcomes the deficiencies of the prior-art devices of thischaracter, and is readily adapted for economical manufacture.

The features of my'inventi'on which I be` lieve -to be novel, willappear more clearly from the following descriptionof various simpleexemplications of my invention, .reference being made to theaccompanying drawings in which,A Y

Fig. 1 is a vertical sectional view of a pump to which my inventionpertains;

Fig. 2 is ahorizontal sectional view'of the pump in Fig. 1 along thelines II--II;

. Fig. 3 is a vertical sectional view through a pump exemplifying myinvention; F ig. iis a horizontal sectional view'of the pump in Fig. 3along the line IV--IV'g Fig. 5 is a detailed sectional view through aportion of the impeller tube and the adj acent housing along the lineV-V in Fig. 3; 'Figs 6 to 10 are sectional views similar to Fig. 5illustrating various modifications of the construction of the impellertube and of the mounting thereof; Figs. l1 and 12 are views similar toFig. 3 illustrating modifications of the invention;

Fig. 13 is a view similar to Fig. et illustrating another modificationof the invention;

Fig. 14: is a detailed sectional view of one vform of a compressionvalve used in my im-v proved pump; and,

A Figs. 15 and 16 are views similar to Fig. 1

trated in the arrangement of .sively contact with the tube 5 andgradually?, `0 roll flat a portion thereof, in the directionf-v 166,548,and in- Germany February i8, 1926.

The operating principle of the type of pump to which my, inventionrelates is i1lus`- In the inner chamber 1 of a pump casing 2 having afluid inlet 3 and an outlet 4, 1s I dispose and elastic tube 5 ofrubber, ori-60' the like. One end of the ltube is fitted into the inletopening; the tube being disposed adjacent to the circular walls'of thecham;

ber 1, and having its other end `terminate y near the outlet .4. Animpeller member 6 255 lin the formof rollers? .arranged to be rotated bya crank member 8- through a shaft" 9 extending through the casing, issorarranged within the chamber as to progresfrom the inlet 3 toward theoutlet 4,. This action of the roller members 7' thus, .to a cer- I tainextent, squeezes the liquid inthe direction towards the outlet 4,thereby forcing the i liquid towards the delivery side 4 of the pump.The two' rollers 7 of the impeller member are so arranged that as onerollerv is leaving the elastic tube 5, the other is just beginning thecompression cycle at the point ofthe tube adjacent the pump inlet 3,thereby preventing backward iiow of the iuid.

A pump. made as described above has a number of disadvantages outlinedabove, and

'it is among the objects of the present inven- 85 tion to so improvethis type of pump as to greatlyincrease'its field of application and atthe same time permit its economic manufacture. v

One .of the disadvantages of the prior-art 9'0 pump is the excessivewear of the iexible impeller tube 5 by reason of 'the squeezing orpinching action that takes' place in the operation of the prior-artvpumps ofthis e aracter. One Jfeature of my invention is the provisionof an improved type of impeller tube having combined therewith a speciallining or insert for increasing its resistance to the wear incident tothe movement of the roller or impellerthereon for reduc- 10o Figs. 1 and2.

casing walls, or through the inner chamber of the casing, or through thelining associated with the impeller tube.

A further feature of the invention resides in the improved means forholding the impeller tube in position withinthe casing through theaction of the elastic lining, and through the suitable mounting meansasso-` ciated therewith. i

Another feature of the .invention resides in the arrangement for causingthe elastic impeller tube to return to its expanded con- -dit1on afterthe passage of the roller over a portion thereof, and theitilization ofa partial vacuum or underpressure in the crank case of the pump for thispurpose. Other features of the invention reside in the provision of animpeller tube that extends directly through between the inlet of thepump and the outlet thereof, thusV permitting complete segregation ofthe fluid that is being impelled in the pump from the crank case.

' This arrangement avoids the necessity for pressure-tight packings andstuffing boxes at the point where the impeller shaft is'to lead throughthe walls of the pump casing.-

lt also prevents the admixture of` grease, 011, or other lubricatingsubstances and the like, that may be employed in the ,pump mechanism tothe iuid that is being Vimpelled through the pump.

A distinct feature of the invention is the provision of an improvedcompression valve at the delivery endl of the impeller tube of the pump.l Y

Still other features of my invention reside in the utilization of thepartial vacuum withi in the crank case' chamber for withdrawing theworking Huid in case the elastic impeller tube should become leaky; theutilization of auxiliary rollers for preventing excessive expansion orinflation of the portions of the impeller tube in whichthe liquid isbeing compressed; and other features which will appear more clearlyvfromthe further description of the several forms of the invention.

Referring to Figs. 3 and 4, the impeller tube 5 has its intake end 11directly attached to the intake or suction pipe l2, and its delivery end13 isdirectly connected to the delivery pipe 14, a compression valve l5being includedin the connection between the deliveryend of the tube andthe delivery pipe thespace adjacent the same,`

Lveaeee 14. The two ends of the impeller tube are preferably so broughtout fromthe circular ortion of.the casing 2 as to avoid sharp ends orangles.

The impeller tube 5 is made of an elastic flexible material, such asrubber, and so arranged as to vretain its expanded, open or hollowshape. It is mounted within the cas-l ing so as to form a substantiallycircular annular body having its outer surface backed against thecircular'inner walls of the casing. The impeller member 7 in the .formof a roller, is supported on a crank member 8 and driven by the shaftQin counter-clockwise direction, the roller surface pressing the innerwall of the impeller tube 5 against the wall of the casing 2. As theresultvof this action of the impeller member the tube is attened at theportion where'the impeller member presses against it, the oint offlattening traveling progressively rom near the intake end ll of thetube toward the delivery end 13 thereof, thereby forcing the fluidwithin the tube in the direction of the arrows 16.

In order to preserve the flexible impeller tube andprevent its ra iddestruction incident to the cylical action of the impeller member 7, thetube is provided with a specialinsert or lining 21, which is so arrangedas to hold the tube fixed in its operating position, with its outerwalls against the walls of the casin 2, and furthermore, to permitcomplete co lapsing of the tube under the action of the impeller member7 without introducing sharp bends in the tube walls, and excessivelystraining the same.

There are a variety of constructions permitting an arrangement of thetube to secure the foregoingobjects. In the construction of Figs. 3 and4, the lining is formed in the shape of a substantially circular flatring arranged inside the tube adjacent the outer wall thereof, the sidesof the circular rim forming somewhat enlarged rounded beads lyingadjacent to the exterior and side walls I of the impeller tube, as shownat the righthand side of the view in Fig. 4. This lining may be made ofsubstantially rigid material, but l prefer to have it made elastic, butless iexible than the tube. It may, for instance, be made of a rubberbody that is harder than the walls of the tube 5. The rigidity of-thelining will in most cases be suflicient to hold the tube in shapeagainst the walls of the casing 2.l However, if necessary, the tube maybe additionally secured against the casing by bolts 22 which clamp thelining towards the casing walls.

The particular shape of the lining in the interior of the tube shown inthe drawing is so chosen that when the inner wall of the tube iscollapsed inwardly and pressed outwards, the inner surface of the liningis substantially co-extensive with the inner surface mensen of the vtubeportion which is to'be pressedv against said lining surface. ln otherwords,

Y the total outer surface of the lining is substantially equal to theinner area of the tube when in collapsed condition, as shown in thelefthand side of the view in Fig. 4. This arrangement prevents pinchingof the tube walls while compressed by the impeller member. It alsosecures Very complete impelling action, since it permits completecompressing or sealing off of the tube under the action of the impellermember pressing against the inner walls of the tube. In this way thesuction and delivery spaces of the pump are completely separated andundesirable reverses of the flow are prevented.

The outer surface of the roller 7 is so shaped as to substantiallyconform to the inner periphery of the lining, or the collapsed conditionof the tube when it is pressed against the lining, respectively. In thepreferred arrangement the width of the lining is so chosen that only arelatively limited portion of the tube at the interior side thereof issubjected to the action of the roller, and is moved between the open andthe collapsed position, respectively, the side walls of the tube and theexterior thereof being sustantially free from any strains.

Under some operating conditions the pressure in the portion of the tubebetween the impeller and the compression valve 15 .may

be so large as to tend to produce excessive inflation of the elastictuba1n order to prevent, and safeguard against, such excessive inflation, Iprovide -the tube w'ith speciall frneans for limiting the inward radialmovement of the innerwalls of the impeller tube. Such means may have.the form of a plurality of guide rollers 25 carried on an eXtension ofthe crank-8, opposite the impeller roller 7. While the impeller rolleris so mounted that the outer surface thereof, contacts with the surfaceof the tube when in collapsed condition, the guide rollers are soarranged asto contact with the impeller tube when it is in open orundeformed condition.

As shown in the detailed view of Fig.' 5, the-lining 21 may be madehollow with a chamber 31 in the interior thereof to permit circulationof a liquid in order to cool the impeller tubeand the associatedportions of the pump, or for any-other purpose, such as to bring thefluid that is impelled in the pump f in a heat-exchanging relation withanother fluid. Cooling of the impeller tube is very often desirable,particularly where the temperature conditions are such that the constantbending of the iiezrible tube produces therein sufficient frictionlosses as to cause a temperature rise beyond an allowable value.

Fig. 5 shows the impeller tube in collapsed or deformed condition, thedash-dotted line' corresponding to the undeformed condition of the tubeafter the roller has moved to clamp the, impeller tube in place againstthe outer casing walls. By reason of the particular shaping ofthe innersurface of the lining and the roller, the tube will be collapsed withoutpinching the side portions thereof between the roller and the casingwalls, and at 'the same time a complete closure of the tube at the pointwhere'the roller acts thereon will be obtained.

Additional cooling of the tube and the associated portions of the pumpmay be secured b circulating through the interior of the cgamber 1 asuitable fluid, for instance, by

means of a pipe connection indicated at 35.-

In the preferred arrangement of my invenvand the lining, and serve toadditionally y tion the pressure within the crank-case chamber 1 around'the impeller tube 5, is maintained below the pressure of the fluidlwithin the impeller-tube. rlhis partial vacuum or pressure differencebetween the interior of the impeller tube and the exteriorl thereof,will assist the tube in returning toits normal undeformed or expandedposition after the roller which flattens the same has passed to anotherportion. lt will also protect against leakage of the tube and lead awayany portions cf the fluid that may getinto the crankcase chamber througha leak. l

In Figs- 6 to 10, there are shown a number lof modiiications of the tubemounting and the associated lining.` ln the construction of Fig. 6 aresult similar to that obtained with the arrangements of Figs. 3 and 4is obtained by making the lining in thev form of two rings, 41 and 42,of rubber or similar elastic material. The rings 41, 42 are disposedopposite each other adjacent the side walls of the tube and are held inplace within the tube between the side walls 43 of the casing whichpartially overlaps the elastic tube and the lining, like in the mountingof tires in motor car Wheels. With such arrangement no furtherattachment of the lining and. the tube is required.

In the modication of Fig. 7 the tube anti the lining constitute aunitary body', a reinforced suitably shaped portion of the tube takingthe place of a separate lining.v

Fig. 8 shows an arrangement for supporting the tube and the lining inannular grooves vbeads for Clamping in the annual grooves of the sidewalls of the casing similar in construction to 'that of Fig. 7.

In the form of the invention shown in Fig. 10, the impeller-tube doesnot have the form of a closed integral tube, but it has a iexibleportion which constitutes the inner wall of the impeller tube, and hasits sides 46 clamped to the side walls 47 of the lining whichconstitutes the other portion of the impeller tube. The clamping of theflexible portion' of the impeller tube to the lining is effected by theoverlapping portions of the casing walls at 48.

In the form of the invention shown in Fig. 11, the impeller tube is madein the form of a substantially closed ring 51 which is split at the top52 where the two ring ends meet and abut against each other. In thisconstruction the suction or intake sideV 53 and the delivery side 54 ofthe pump of the impeller tube are separated by enlarged portions 54 ofthe lining. The lining ismade of two halves which may be separatelyinserted into the tube through the ends thereof at the point 52 where itis split, the enlarged portions of the lining at 54 -servingas plugs toclose the two ends of the tube.. The lining is suitably clamped to thecasing walls by the bolts 22, a sleeve 55 being fitted over the two tubeends at the point where they meet to hold these portions securely inplace.

The'entire arrangement is such that when the inner wall of the impellertube is considered in collapsed position adjacent to the inner surfaceof the lining, it will have a. substantially circular surface aroundthecenter of rotation of the impeller member 7. With the foregoingconstruction the impeller roller 7 remains continuously in contact withthe iexible tubular member, whereas, in the arrangement shown in Figs.-3 and 4, the roller had to pass over a gap at the portion between I Athe intake and delivery endsof the impeller tube.

In the form of the invention shown in 12, bot-h the tube and the liningform a complete circle, whereas, in the construction shown in Fig. 11the impeller tube is of somewhat elongated shape. In the construction ofFig. 12, the inner surface of the tube is tightly secured to the liningat 56, by cementling, rivetin ,or otherwise, in order to separate thedelivery and suction portions of the impeller tube. The circularconstruction of the ring is helpful in preserving the flexible tubularmember and extending the life thereof.

Both in the-.constructions of Fig. 11 and Fig.l2, the suction anddelivery pipes are back-flow o connected to the ends of the tube bymeans of radial attachments 57 and 58 disposed in radial direction in amanner similar to the valves of pneumatic tires of automobiles and thelike.

The form of the invention shown in Fig. 13 is particularly suitable forhigh pressures,

. the casing 61 being so shaped as to practically enclose and surroundthe entire outer walls of the impeller tube 5, leaving only acomparatively narrow gap 62 through which the impelling roller 7 maypress against the tube and impel the liquid therein.

'In this construction the casing walls 61 are shown provided with hollowpassages 63 adjacent to the portions where they contact with theimpeller tube 5 to permit circulation of additional cooling liquidthrough said passages, or for any other heat-exchanging operations.

The direct connection of the two ends of the impeller tube to thesuction pipe and the 'delivery pipe, respectively, as shown in Figs. 3,etc., is very desirable from the viewpoint of maintaining the iiuid thatis impelled by the pump completely segregated from the moving mechanismsof the pump and of dispensing with packings, stutting boxes, and thelike. The working Huid is thus entirely enclosed by an air tight elasticcompression chamber entirely dispensing with glands, stutin boxes, andthe like.

In the preferred embodiment of the invention, I provide in the deliveryend of the impeller tube a compression valve, such as indicated at Fi s.3 and 11, in order to prevent the liquid into the impeller tube in casea leak should develop therein, and also in order to avoid continuoussubjection of the impeller ytube to the full pressure of the Ycompressedfluid. The provision of the comcompression valve, is utilized.

The compression valve, as shown in Fig. l 3, is formed by an enlargement71 of the elastic lining 21 near the delivery end oi the impelling tube.This enlargement 71 constitutes a substantially circular body which hasa hollow tubular chamber 72 at its upper end. The delivery pipe 14 isdirectly connected to the upper end of the tubular chamber 72 which isprovided at its lower end with a plurality of perforations 73 extendingradielly outward through the walls of the chamber.` The delivery end 13of the impeller tube is fitted over` the enlarged portion 71 of thelining 'and forms an enclosure aroundl the space provided with theperforations 73.

In operation, the liquid compressed inthe impeller tube by the action ofthe impelling roller 7 will be impelled towards the delivery end of theimpeller tube, and cause said end against the to be im'iated at thespace around the perforations 73, thus delivering the fluid through saidperforations into the hollow chamber l752. and therethrough into thedelivery pipe 14;. 4A suitable clamping ring 75 around'the 'delivery end13 of the impeller tube may serve to hold the same sealed to theadjacent portions of the valve.

In Fig. 14 is shown another valve construction comprising a tubularvalve chamber 81 having a threaded outer surface over which the deliveryend 13 of the impeller tube is fitted and held clamped by means of aring 82. A closure member 83 is held pressed co-operating valve seat inthe valve chamber 81 by means of a spring 85 which is held in aco-operating portion 86 of the valve to permit the adjustmentl of thespring 85 in a familiar manner. The valve chamber is held in placewithin the pump cas-v ing by means of a sritable flange 87. The insert21 within the tube has an enlarged portion 88 at the end thereofadjacent to the lower'part of the valve chamber 81 in order 25 to makethe dead space at the endl of the compression part of the impeller tubeas small as possible, as seen in the drawing in which the impeller tube5 is shown in deformed position, being pressed down by the impellingroller 7 corresponding to its position at the end of the compressioncycle. The shape of the impeller tube in undeformed condition isindicated by the dash-.dotted line 89.

One of the reasons for the excessive wear of lthe impeller tube in thepumps as made heretofore, is the tangential pull on the material behindthe roller and the tendency to form a wave in front of the roller, thelatter leading very often to puckering and pinching of the tube.

In accordance with my invention the impeiling means are so designedwithv respect to the impeller tube as to eliminate this drawback. Tothis end I so correlate the size and the shape of the impeller meanswith respect to the dimensions and shape of the impeller tube that themovement of the roller on the tube is not accompanied by any forcestending t0 pull the tube walls in a direction in which 5o it would causethe formation of folds, or the like. In theconstruction shown in Figs.3,

etc., Iattain this object by making the di- .'ameter of the im ellingroller 7 substantially e ual or larger t an one-halfv of the internaldiameter of the tube when in depressed condition.

In Fig. 15 there is illustrated diagrammatically the case where thediameter of the impelling roller 7 is half the diameter of the basecircle 5 upon which it is rolled, corresponding to the tube5 in thedeformed condi tion. The curve described by a point 93 on the rollercircle 7 is in this ease a hypocycloid in the shape of a straightradially-extending In the case illustrated by 16- wherein the diameterof the rolling circle is more than one-half the diameter of the basecircle 5', l

the curve described b a point 93 on the rolli ing circle is acurvehypocycloid 92 which contact with the tube without applying any pressureto the walls thereof. -Under such conditions the walls of the tubeswould be subjected only to radial forces corresponding to the arrow 95,and would be free from tangential stresses.

I-Iowever, if the roller is pressed against the elastic tube, thematerial of the latter will be rolled out in the direction of the rollermotion, even if n0 sliding should occur. Accordingly, there will be atendency to form puckers and the tube walls will be subjected to acertain amount of tangential pull, which would be, however, only aIfraction of the pull ,that would be present in case the diameter of theroller were made' less than one-half of the diameter of the base circle.

By making the diameter of the roller greater than one-half the diameterof the base circle, the foregoing rolling action can be completelycompensated as seen from the diagrammatic view in Fig. 16. In the lattercase the point 93 will not move in radial direction, but will be forcedbackward, thus offsetting the force component which tends to move thematerial in forward direction when compressed by the roller. By suitablydimensioning the roller, the formation of puckers may thus be completelyprevented, and the useful life of the tube extended.

My invention is susceptible of many other I modifications than thosedescribed and speciiically pointed out hereinabove, and it is my desirethat the appended claims be given a broad construction commensurate wlththe scope of my invention which, as shown hereinabove, not only avoidsthe difficulties met in the prior-art constructions, but embodies inaddition a number of features which greatly extend the usefulness ofthe'type of pump under consideration. .,l .l

The particular construction of the pump in which the impelled fluid iscompletely se regated from contact with the rotating or ot er Amovingmembers of thepump mechanism,

safeguards the fluid against contamination with the impurities, such asoil, grease, etc. This' feature makes the pump particularly suitable forimpelling chemically active fluids the pump also particularly adaptedfor use in connection with poisonous substances, as the escape of suchsubstances is positively excluded. vThe absence of packings and pointsof leakage makes the pump also very effective for producing high vacua.

I claim as my invention:

l. In a pump comprising a tubular impeller chamber of elastic materialand means for propelling fluid through said chamber by successivelyflattening portions of said tubular chamber in the direction in 'whichthe fluid is to be moved, means associated with and disposed in saidchamber and providing for complete closure of any section thereofWithout introducing sharp bends into the flexible Working Walls thereof.

2. In a pump comprising an impeller tube having an-elastic wall andimpeller means for progressively closing sections of said tube bysuccessively compressing portions of the flexible Wall in the directionin which the fluid is to be impelled, means associated with and disposedin said tube to constitute a relatively stable support for the flexibleWall thereof when in depressed condition.

Si. In a pump comprising an impeller tube having an elastic Wall andimpeller means for progressively closing sections of said tube bysuccessively compressin portions of the flexible walls in the directionin which the fluid is to be impelled, means associated with said tube toconstitute a relatively stable sup port for the flexible Walls thereofwhen in depressed condition, said support being rounded to prevent sharpbends in the flexible portions of the tube.

4. In a pump comprising an impeller tube having a flexible wall portionand impelling means for progressively closing said' tube by successivelycompressing the flexible walls thereof in the direction in which thefluidis to be impelled, a lining associated with said vtube to act as asupport forvsaid flexible Wall when in deformed condition, said liningbein relatively rigid with respect to the flexible portions of said tubeand permitting complete flattening of sections o said tube withoutintroducing sharp bends in the flexible por-A 4 tions thereof.

6. `In a pump comprising an impeller tube having a flexible Wall portionand impelling means for progressively closing said tube by successivelycompressing the flexible wall thereof in the direction in which thefluid is to be impelled, a lining associated with said tube to act as asupport for said flexible Wall when in deformed condition, said liningbe` ing relatively rigid with respect to the flexible `.portions of saidtube and permitting complete flattening of sections of said tube withoutintroducing sharp bends in the flexible portions thereof, and meansassociated with said lining for cooling the same.`

7.- In a pump comprising an impeller tube means for progressivelyclosing said tube by successively compressing the flexible Wall thereofin the direction'in which the fluid is to be impelled,a-liningassociated Withsaid when in deformed condition, said liningbeing relatively rigid with respect to the flexible portions of saidtube and permitting complete flattening of sections of said tube.-vvitliout introducingsharp bends in the flexible portions thereof, saidlining having a hollow conduit for circulating therethrough a fluid inheat-exchanging relation therewith.

8. In a ump comprising an impeller tube having a exible wall portion andimpelling meansfor progressively closing said tube by v9. In a pumpcomprising an impeller tube.

having a exible Wall portion and means for impelling a fluid in saidtube by progressively flattening sections of said tube in the direc- .80having a. flexible Wall portion and impelling,

.85 tube to act as a support for said flexible Wally liti tion in whichthe fluid is to be impelled, a

substantially rigid casing having Walls supporting the `portions of saidtube a ainst which the flexible portions thereov are pressed, and meansfor holding the portions of said tube adjacent to the Walls of thecasing in substantially rigid condition thi-oughout the operationthereof. f

10. In a pump, a substantially circular casing, a substantially annularimpeller tube adjacent to the Walls of said casing, means for holdingone Wall of said tube in substantially rigid position against the Wallsof said casing, the opposite Wall of said tube being relatively flexibleand arranged to be compressed against the rigid Wall .portion to permitcomplete flattening of the sections of rigid position against the wallsof said cas ing, the opposite wall of said tube being rela- -to saidtube as to tively flexible and arranged to be compressed against therigid wall portion to permlt complete flattening of the sections of saidtube, 1m eller means arranged to be driven lalong sai tube tosuccessively flatten portions there-l of in the direction in which thefluid is to be' impelled, said tube being so shaped and supported as toprevent sharp bends in the leXile portions thereof under the action ofsaidimpeller means, bead members, extendine along said tube, and'meansassociated with said casin for clamping said bead members thereto to oldsaid tube in position. v-

12. In a pump, a substantially circular casing, a substantially annularimpeller tube ad\ jacent to the walls of said' casing, means for holdingone wall of said tube in substantially rigid position against thewallsof said casing, the opposite wall of said tube being rela-' tivelyflexible and arranged to be compressed against the rigid wall Aportionto permit complete flattening of the sections of said tube, impellermeans arranged to be driven along said tube to successively flattenportions thereof in the direction in which the fluid is to be impelled,said tube being so shaped and supported as to prevent sharp bends in theflexible portions thereof under the action of said impeller means, beadmembers extending along said tube, and means associated with said casingfor clamping said bead members thereto to hold said tube in position,said impeller means being so arranged with respect substantiallyeliminate tangential pull of the iexible tube walls incident to theprogressive movement of the impelling means. l

13. In a rotary pump comprising a substantially circular impeller tube,a fluid intake connection at one end of said tube and a fluid deliveryconnection at another end of said'tube, said tube being collapsibletopermit successive closure of the sections thereof in the direction fromthe intake end tc the delivery end thereof -to impel the fluid, animpeller roller movable on said tube to progressively close sectionsthereof and impel the fluid towards the delivery end of said tube, saidimpeller roller being so dimensioned. with respect to the path on whichit rolls that the force component exercised by said roller on theco-operating Walls of said tube is permit successive Athereof in thedirection from said tube,

directed substantially walls of said tube in un eformed condition.

stantially circular impeller tube, a fluid intake connection at one endof said tube and a fluid delivery connection at another end :of saidtube, said tube being collapsible ,y to

closure of the sectionsv the intake end to the delivery end thereof toimpel the fluid, an impeller roller movable on said tube'toprogressively close sections thereof and impel the fluid towards thedelivery end of said tube, said impeller roller being so dimensionedwith respect to the path' on which it rolls asto substantially eliminatepull on the erpen'dicular to the 14. In a `rotary pump comprising a sub#flexible portion of said tube in the directionv of the movement of theroller.

15. In a rotary pum comprising a substantially circular impe ler tube, afluid intake connection at one end yof said tube and a fluid deliveryconnection at another end of said tube, said tube being .collapsible topermit successive closure of the sections thereof'in the direction from'the intake end to the delivery end thereof to impel the Huid,

an impeller roller movable on said tube to progressively close sectionsthereof and impel the fluid towards the delivery end of saidtube, thecurvature of said roller being'so related to the curvature of the pathonl which it rolls as to substantially eliminate forces tending to pullthe flexible walls of said tube in the direction of the impellermovement.

16. In a rotary pumip comprisinga subst-antially circular lmpeller tube,take connection at one end of said tube and a fluid delivery connectionat another end of said tube being collapsible to Vpermit successiveclosure of the sections thereof Ain the direction from the intake end tothe delivery end thereof to impel the fluid, an impeller roller movableon said tube to progressivel close sections thereof and impel the fluidtowards the delivery end of said tube, said impeller roller being sodimensioned with res ect to the path on which it rolls that the orceexerted vby a point o'f the roller on the cooperating walls of the tubeis directedsubstantially perpendicular to said path or in a directionback thereof.

17. In a rotary pump comprising a substantially circular impeller tube,a fluid intake connection at one end of said tube and a fluid deliveryconnection at another `end of said tube, said tube being collapsible topermit successive yclosure of the sections thereof inthe direction fromthe intake end to the delivery end thereof to impel the fluid, animpeller roller movable on said tube to progressively close sectionsthereof and impel the fluid towards the delivery end of said tube, thediameter of said roller being equal to one-half or more than thediameter of the a fluid in-` path on which it isarranged to'roll on saidtube.

18. In a pump comprising a casing and an impeller tube disposed withinsaid casing, a fluid intake connection at vone point of said tube and afluid delivery connection at another point of said tube to directCirculation impeller tube disposed Within said casing,`

a fluid intake connectionat one point of said tube and a fluid deliveryconnection at another point of said tube to direct circulation of saidfluid under substantial segregation from the other portions of saidcasing, said tube having a flexible wall arranged to be progressivelycompressed, and impeller means for progressively compressing portions ofsaid flexible wallin the direction from the intake point of said tube tothe de- 4liver point thereof to impel a fluid towardslsaid deliverypoint, said casing exterior of said tube being maintained. at a pressurebelow the pressure of the duid within said tube. 20. In a pump, animpeller tube having l a fluid intake connection at one point thereofand a fluid delivery connection at another point thereof, said tubehaving a flexible wall permitting successive flattening of portions ofsaid tube between the intake point'and the delivery point to impel thefluid therein, an impeller means successively acting on said portions ofthe flexible wall toimpel said @incasso ment to said impellermeansand'said guide means along said tube.

22. In pump apparatus, a collapsible fluidimpeller tube, means foreffecting yprogressive collapsing of said tube from the inlet end to theoutlet end thereof, and valve means y disposed within and cooperatingwith the outlet end of said tube to prevent backward flow of fluid withrespect thereto.

23. In pump apparatus, a collapsible fluidimpeller tube, means for'effecting' progressive collapsing of said tube from the inlet end -tothe outlet end thereof, and a member disposedwithin the outlet end ofsa'id tube and providing a valve seat for such end, said outlet endcooperating with said member in such manner as to provide a valve actionwith respect to said tube to prevent backward fluidflow in said tubewhile permitting of forward fluid-flow therein. Y

24. In pump apparatus, a fluid-impeller tube having a collapsible wall,means for effecting progressive collapsing of said tube from the inletend to the outlet end thereof,

and supporting means for said wall disposed within said tube, the end ofsaid supporting means adjacent the outlet end of said tube cooperatingwith the latter to provide a valve action with respect to said tubepreventing backward fluid-flow therethrough while permitting of forwardfluid-flow through the same.

.In testimony whereof I have hereunto subscribed my name at Zurich,Switzerland, on the 13th day of January, A. D. 1927.

vADOLPI-I BAUMANN.

, los

fluid and compress the same in the portion of the tube between saidimpeller means and y the delivery point thereof, and guide means l forsupporting the undeformed Iportions of said impeller tube to preventexcessive inflation thereof under the action of the pressure of thefluid in the interior thereof.

21. In a pump, an impeller tube having a fluid intake connection and afluid delivery connection, said tube having a flexible wall permittingsuccessive flattening of portions of said tube to impel a fluid withinthe same, impeller means for progressively compressing the flexibleportions of said tube and impel said fluid, and guide means actingagainst the flexible portions of said tube outside the portion'compressed by said impeller means to `prevent excessive inflation ofsaid tube incident to the compression of fluid there'- in, and meansimparting a progressive move-

